zesting question

I plan on zesting some fruit in my american wheat kit.At what point do you add this in and for how long,how much do you add,i would like to use either tangerines or oranges.

I would add it after primary fermentation to try to retain as much flavor from it as possible. As to how much I think it would all depend in your personal preference and style if beer your spicing. So I can't help much on amount. I'm sure somebody else who's more experienced with zesting their beer can fill in the blanks.

I generally see folks recommend around 2 tablespoons. I made an orange pale and added zest from two average tangerines and it was great.

For orange zest, bitter, aka sour orange is usually recommended. I've put the zest of two bitter oranges in a 5 gallon batch of a strong beer with some residual sweetness and it was orangey enough that I don't think I'd ever add more than that. On a couple of occasions I've added the zest of two (Persian) limes. Those came out well balanced, with a hint of lime flavor/aroma.

When I add zest I put the zest in a hop bag, put that bag in a small jar and just cover it with vodka. Leave that to steep for a few days and add the zest and the vodka to my beer a week before bottling.